1. Field of the Invention
The present invention relates to a facsimile control apparatus.
2. Description of the Related Art
For reducing power consumption of a fax control unit (FCU), there is known a technology to shut off most of power supply to a central processing unit (CPU) (a main control unit), a modem, and a secondary circuit, which require a high amount of electric power, but instead install an energy-saving CPU. In this technology, upon receipt of ringing from a telephone circuit, the FCU first inputs a ringing signal to the energy-saving CPU, and then the energy-saving CPU inputs an interrupt signal to the modem, thereby restoring the modem and the secondary circuit to normal state.
However, such a conventional energy-saving system has problems that the energy-saving CPU consumes electric power eventually and the cost is increased by the installation of the energy-saving CPU. Furthermore, in order to return the modem, the secondary circuit, and the main control unit from an energy-saving mode, any parts for detecting an interrupt signal from the energy-saving CPU have to be continuously supplied with electric power, and, after all, electric power is consumed.
For example, Japanese Patent No. 3850214 discloses a method in which an additional energy-saving CPU is installed and power supply to a modem, a secondary circuit, and a main control unit is shut off for the purpose of reducing power consumption of an FCU. However, the problems that the energy-saving CPU consumes electric power and the cost is increased by the installation of the energy-saving CPU are not resolved. Furthermore, any parts for detecting an interrupt signal from the energy-saving CPU have to be continuously supplied with electric power to return the modem, the secondary circuit, and the main control unit from the energy-saving mode.
Therefore, there is a need for a facsimile control apparatus capable of achieving an energy-saving mode and returning from the energy-saving mode without an energy-saving CPU.